<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 200px;
            height: 50px;
            background-color: #f77979;
            transition: all 1s;
            margin: 200px auto;
        }

        div:hover {
            width: 1200px;
            height: 600px;
            border-radius: 10px;
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>